Media: China makes breakthrough in super-heavy-lift rocket development With Stainless Steel Tanks

A key Chinese rocket manufacturer has made significant strides in developing stainless steel propellant tanks for future reusable launch vehicles, marking a milestone in the country’s space ambitions.

The China Academy of Launch Vehicle Technology (CALT), a state-owned entity under the China Aerospace Science and Technology Corporation (CASC), recently completed prototype tanks measuring 5.0 and 10.6 metres in diameter, Caliber.Az reports, citing SpaceNews.

The larger tank, unveiled in April, is being hailed as a major step forward in the development of the Long March 9—China’s next-generation super heavy-lift rocket intended for lunar and Mars missions.

According to a now-deleted CALT statement, the 10.6-metre-wide, 9.0-metre-tall tank represents a “major breakthrough” and is central to plans for a reusable rocket comparable to Spacex’s Starship. High-level officials from China’s space agency were present at the prototype’s unveiling.

Stainless steel is gaining traction within China’s launch sector due to its suitability for low-cost, reusable rockets. However, CALT acknowledged that the material presents engineering challenges, including weld deformation and springback, compared to conventional aluminium alloys. 

The institute claims to have achieved multiple technical advances in forming, welding and assembly processes.

The motivation behind the 5.0-metre-diameter tank remains unclear, though it may be linked to the Long March 10 programme, targeted at crewed lunar missions and based on the Long March 5 architecture.

China’s growing commercial space sector is also embracing stainless steel. Landspace’s Zhuque-3 is aiming for an orbital debut in late 2025, while newer entrants like Lightyear Exploration and Space Epoch are investing in similar technologies.

By Aghakazim Guliyev